[PULP-2089] Add PEP 440 version_specifier filter

CHANGES/1277.feature

@@ -0,0 +1 @@
+Added `version_specifier` filter to package content API for PEP 440 version matching.

pulp_python/app/viewsets.py

@@ -5,7 +5,9 @@
 from django_filters import CharFilter
 from django_filters.rest_framework import filters as drf_filters
 from drf_spectacular.utils import extend_schema, extend_schema_view
+from packaging.specifiers import InvalidSpecifier, SpecifierSet
 from packaging.utils import canonicalize_name
+from packaging.version import InvalidVersion, Version
 from rest_framework import status
 from rest_framework.decorators import action
 from rest_framework.mixins import (
@@ -466,6 +468,28 @@ class NormalizedNameInFilter(drf_filters.BaseInFilter, NormalizedNameFilter):
     """In-filter that normalizes each input value and queries name_normalized."""
 
 
+class VersionSpecifierFilter(CharFilter):
+    """Filter that matches versions against a PEP 440 specifier string."""
+
+    def filter(self, qs, value):
+        if not value:
+            return qs
+        try:
+            spec = SpecifierSet(value, prereleases=True)
+        except InvalidSpecifier:
+            raise ValidationError(
+                {"version_specifier": f"Invalid PEP 440 version specifier: {value}"}
+            )
+        matching_pks = []
+        for pk, version in qs.values_list("pk", self.field_name):
+            try:
+                if Version(version) in spec:
+                    matching_pks.append(pk)
+            except InvalidVersion:
+                pass
+        return qs.filter(pk__in=matching_pks)
+
+
 class PythonPackageContentFilter(core_viewsets.ContentFilter):
     """
     FilterSet for PythonPackageContent.
@@ -474,6 +498,10 @@ class PythonPackageContentFilter(core_viewsets.ContentFilter):
     name = NormalizedNameFilter(field_name="name_normalized", lookup_expr="exact")
     name__in = NormalizedNameInFilter(field_name="name_normalized", lookup_expr="in")
     name__contains = CharFilter(field_name="name", lookup_expr="contains")
+    version_specifier = VersionSpecifierFilter(
+        field_name="version",
+        help_text="Filter by PEP 440 version specifier (e.g., >=2.4,<3.0 or ~=1.26)",
+    )
 
     class Meta:
         model = python_models.PythonPackageContent

pulp_python/tests/functional/api/test_version_specifier_filter.py

@@ -0,0 +1,28 @@
+import pytest
+
+from pulp_python.tests.functional.constants import PYTHON_SM_PROJECT_SPECIFIER
+
+
+@pytest.mark.parallel
+def test_version_specifier_filter(python_bindings, python_repo_with_sync, python_remote_factory):
+    """Test filtering content by PEP 440 version specifier."""
+    remote = python_remote_factory(includes=PYTHON_SM_PROJECT_SPECIFIER)
+    repo = python_repo_with_sync(remote=remote)
+
+    result = python_bindings.ContentPackagesApi.list(
+        repository_version=repo.latest_version_href,
+        name="Django",
+        version_specifier=">=1.10.2,<1.10.4",
+    )
+    versions = {c.version for c in result.results}
+    assert "1.10.2" in versions
+    assert "1.10.3" in versions
+    assert "1.10.4" not in versions
+
+
+@pytest.mark.parallel
+def test_version_specifier_filter_invalid(python_bindings):
+    """Test that an invalid specifier returns a 400 error."""
+    with pytest.raises(python_bindings.ApiException) as exc:
+        python_bindings.ContentPackagesApi.list(version_specifier=">=invalid!version")
+    assert exc.value.status == 400